Description from Flora of China
Herbs perennial, glabrous. Stems ascending, quadrangular, 10--40 cm tall, branched, glabrous; sterile axillary branches present. Leaves sessile, lanceolate, 3--4(--5) cm × 3--6(--8) mm, abaxially green, both surfaces glabrous, midvein raised abaxially, base rounded or cuneate, apex acuminate. Flowers in terminal cymes, axillary on rachillae; peduncles long; bracts white, ovate-lanceolate, 2--3(--6) mm, membranous, apex long acuminate. Pedicel 1--1.5 cm. Sepals 5, lanceolate, ca. 5 mm, 3-veined, margin membranous, apex long acuminate. Petals 5, shorter to slightly longer than sepals, 2-cleft nearly to base. Stamens 10, shorter than petals; anthers purplish or yellow-brown. Ovary ovoid-globose; styles 3, linear. Capsule slightly shorter than to as long as persistent sepals, 6-valved. Seeds brown, ovoid, slightly compressed, tuberculate. Fl. Apr--Jul, fr. Jun--Aug.
Kozhevnikov described Stellaria merzbacheri (Novosti. Sist. Vyssh. Rast. 20: 105. 1983) based on a specimen from the Tian Shan region of Xinjiang. It would key out closest to S. discolor based on its glabrous stems and narrowly ovoid leaves (ca. 1.4 cm × 5–6 mm). Other features of this taxon include sepals 2.5–3.5 mm, slightly shorter than the petals, with a broadly membranous margin and indistinct veins. The present authors have seen no material of this taxon.
Montane grasslands, forest margins, wet places in forests; ca. 3000 m. Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, Shaanxi [Japan, Mongolia, Russia].